9600

• UCREFRP Catalog Number: 9600
• Author: Brown and Caldwell.
• Title: Phase 2 Coordinated Facilities Water Availability Study for the Endangered Fishes of the Upper Colorado River - Final Report.
• USFW Year: 2003.
• USFW - Doc Type: \
• Copyright Material: NO

F-7
L
1

t
i_]

1

1

Dillon, Williams Fork and Wolford Mountain Reservoirs. These differences would overstate the
availability of water for release from these reservoirs for meeting the 20,000 acre-foot goal. Rather
than continue to investigate and debate the need for further refinements to the model, it was
determined that time would be better spent working on what could be done to meet the 20,000 acre-
foot goal.
FEASIBILITY OF EXPANDED CROPS ALTERNATIVES
From an engineering and economic perspective, the following alternatives could supply the 20,000
acre-feet to the 15-1\ile Reach when required during the study period, at reasonable costs:
¦ Alternative 1a: Green Mountain Reservoir reduced winter power operations.
¦ Alternative 1 a: Green Mountain Reservoir conjunctive pool operations.
¦ Alternative 1 a: Preemptive release and water carried over in Green Mountain
Reservoir.
¦ Alternative 1d: Modify CBT West Slope Facilities Operations.
¦ Alternative 1e: Denver Water system modified operations.
¦ Alternative 1 f Bypass diversions to storage.
¦ Alternative 1g: Reduce constraints on CROPS.
The StateMod model calculated that the effects of supplying the 20,000 acre-feet on reservoir storage,
reservoir yield, reservoir operations, hydropower generation, water deliveries, channel constraints, and
the Check Case Settlement would vary among these alternatives. These effects are briefly summarized
in this report and presented in detail in the Technical Memoranda. The results discussed below and in
the Technical Memoranda assume that the StateMod model accurately simulated reservoir operations
in this study. Some study participants have questioned that assumption. However, the study
participants agreed the studies were sufficient for their purpose and to document the results of the
study in order to move on to discussing what can realistically be accomplished to meet the 20,000 acre-
foot goal.
The study showed that the above alternatives were generally able to replace the 20,000 acre-feet
release/bypass by diverting to storage under the reservoirs' refill rights. This replacement was
generally done within a period of several months. In some cases (e.g. Granby Reservoir) the
replacement was not completed for several years. In the case of Granby Reservoir, replacement of the
20,000 acre-feet release/bypass to the 15-Mile Reach was probably delayed because of limited
availability of storable inflow in those years when releases were made. In general, however,
replacement of the 20,000 acre-feet by diverting to storage under the reservoirs' refill rights. proved to
be more efficient, effective, and less costly, than some of the measures incorporated into the above
alternatives for providing sources of replacement water for the 20,000 acre-feet release/bypass.
' Because of this, replacement of the 20,000 acre-feet should be done by diverting to storage under the
reservoirs' refill rights rather than utilizing some of the specific strategies included in the above
alternatives for replacement. One issue that will have to be addressed is that most existing refill rights
PAData\GEN\CWCB\19665\Report Phase 2\F1na1Report9.03\Final_CFOPS_Report(9-03).doc 4